In the new Netflix series “Atypical,” Jennifer Jason Leigh portrays the mother of a teen on the autism spectrum, played by Keir Gilchrist. Gilchrist tells Kathie Lee and Hoda that he had “a lot of friends on the spectrum,” which informs his performance; Leigh says she likes working on a series as opposed to a film because “as an actor, it’s fun to have that long of an arc.”